N.Y. Comp. Codes R. & Regs. tit. 15, § 47.2 – Vehicles subject to law.

(a) The rearmost wheels of the following vehicles or combinations are required to be equipped with splash guards:
1. (1) commercial trucks;
2. (2) combinations of a commercial truck and trailer, and including a utility or house trailer drawn by a commercial truck;
3. (3) combinations of a tractor and semitrailer; and
4. (4) tractors operating without a semitrailer.
(b) The following vehicles or combinations are not required to be equipped with splash guards:
1. (1) Combinations of passenger car and trailer.
2. (2) Suburban vehicles or station wagons.
3. (3) Vehicles or combinations designated as “special purpose commercial” motor vehicles, and registered under schedule F of subdivision 7 of section 401 of the Vehicle and Traffic Law.
(c) Splash guards are not required on vehicles so designed and constructed that the requirements set forth in section 47.3 of this Part are accomplished by reason of fender or body construction or other means of enclosure.